This invention relates to aqueous cleaning liquids or pastes which are stable both in their effect and in storage and which contain in particular chlorine-stable surfactants, an abrasive component and/or an active chlorine donor, dyes and fragrances and also amorphous calcium aluminum silicate precipitated in situ.
Large quantities of scouring agents are used in the cleaning of heavily soiled, mechanically resistant surfaces both in the home and in industry. Bleaching and non-bleaching scouring powders in a ratio of approximately 50:50 are available on the market for this purpose. At the present time, non-bleaching scouring powders are being replaced to an increasing extent by scouring liquids. Hitherto, however, a geniune, liquid and bleaching scouring agent has never been available on the market. The reason for this would appear to lie in the difficulty of formulating products of this type in a form in which both the suspension itself and also its active bleaching component remain stable.
Combined bleaching and cleaning or scouring agents are supposed to develop this bleaching and cleaning or scouring effect in a very short space of time, that is, during their use and at room temperature. Compounds which release active chlorine are commercially available as bleaching components for liquid agents of the type in question which satisfy these requirements and of which the loss of activity in aqueous solution is tolerable. Now, to produce a liquid cleaning or scouring agent, particularly one based on compounds of the above-mentioned type, it was necessary to find a medium which is unaffected above all by aqueous solutions containing active chlorine and which on the one hand is capable of permanently suspending even particles of abrasive and, on the other hand, shows surface-active properties so that, in addition to the pure scouring and/or bleaching effect, the liquid cleaning or scouring agent also develops the cleaning effect, with respect to fat-containing soil, required by the consumer.
U.S. Pat. No. 4,248,728 already describes scouring pastes containing crystalline sodium aluminum silicate and optionally compounds containing active chlorine and/or mineral abrasives. Although abrasive-containing scouring pastes can be obtained in accordance with the teaching of this U.S. Patent using additions of swellable magnesium aluminum silicate, the abrasives settle out irreversibly after storage to form a solid sediment, despite vague statements to the contrary. As a result of this phenomenon, the product can no longer be used.
According to U.S. Pat. No. 4,235,732, expandable clays are used for stabilizing suspensions of hypochlorite-containing liquid scouring agents. However, expandable clays are attended by the disadvantage that they have such a strong thickening effect that they can only be used in small quantities and are only suitable for stabilizing suspensions of abrasives of lower specific gravity, namely the expanded perlites preferably and exclusively used in the above-mentioned U.S. Patent. However, they cannot be used for stabilizing abrasives of higher specific gravity, such as powdered quartz or marble, which are also mentioned therein and are normally used in genuine scouring agents, in the quantities required to obtain an adequate scouring effect. Abrasives as heavy as these settle even through thixotropic pastes and form an irreversible deposit. Another disadvantage lies in the fact that, on account of their natural origin, these expandable clays generally contain small quantities of impurities which, through catalytic reactions, accelerate the decomposition of compounds containing active chlorine in aqueous solution and, hence, adversely affect their long-term stability of action in the liquid cleaning or scouring agents.
Published European Patent application No. 0 009 942 A 1 also describes pourable liquid active-chlorine-containing scouring agents which contain a combination of anionic and nonionic or ampholytic surfactants and an electrolyte. However, the stability of these scouring agent suspensions with respect to chlorine is inadequate for retail products.